I've heard a few people ask the question, "Why doesn't God just show himself to the world? Then people would believe in him"
Well, he did show himself, many times, but we weren't interested. It didn't work.When the first murder on earth happened, God Himself did show up and try to reason with the killer.
Then the LORD said to Cain, "Where is Abel your brother?" And he said, "I do not know. Am I my brother's keeper?" Genesis 4:9
God gave Cain a chance to confess and tell God he was sorry he did it. That isn't what happened; God allowed Cain to move far away and build his own city.
Just seeing God personally and talking with him doesn't change people. Being sure there is a God who made the world and is righteous, doesn't change people. Even seeing someone rise up from a grave, awake from the dead, doesn't change people.
"But he (Jesus) said to him, 'If they do not listen to Moses and the Prophets, they will not be persuaded even if someone rises from the dead.'" Luke 16:31
God knows what we are like. He knows when it will help to reveal himself and when it won't. That is where our faith comes in; we can believe he knows what he is doing.
Almost everyone knows the story of the Exodus and all the miracles God performed through Moses. Did this change the Egyptian King's heart? No. But the world heard the story and many did come to God; however the nearby nations did not leave their idols and neither did the Egyptians.
The king of Babylon set up a golden image and commanded everyone to bow down and worship it or be thrown into a fiery furnace. He called all the important people of his realm.
"Then the satraps, the prefects and the governors, the counselors, the treasurers, the judges, the magistrates and all the rulers of the provinces were assembled for the dedication of the image that Nebuchadnezzar the king had set up; and they stood before the image that Nebuchadnezzar had set up."
Three men from Jerusalem refused to bow and were thrown into the fire. But God was with them in the furnace and didn't allow them to die. The king called them out. Here was proof in the living God.
"The satraps, the prefects, the governors and the king's high officials gathered around and saw in regard to these men that the fire had no effect on the bodies of these men nor was the hair of their head singed, nor were their trousers damaged, nor had the smell of fire even come upon them.
Nebuchadnezzar responded and said, "Blessed be the God of Shadrach, Meshach and Abed-nego, who has sent His angel and delivered His servants who put their trust in Him, violating the king's command, and yielded up their bodies so as not to serve or worship any god except their own God."
Daniel Chapter 3.
Still, the king did not give his life to God until he became ill, and then he finally did. The known world at the time knew the whole story and did they become believers? We don't know. Probably some did, but the worship of the Jew's God did not take over the world.
Finally, God sent his Son into the world. God Himself was with us. He went about doing good, as the Bible says. He worked many miracles and even the voice of his Father was heard. Did this persuade the majority of people? No, instead the leaders plotted and killed God. He showed himself and we killed him.
Evidence alone will not persuade anyone to follow God. There must be a longing in the heart for something better; for something beautiful. We can't find that beautiful thing here. Yes, nature is beautiful and people can be beautiful; but they can't satisfy that emptiness and longing inside of us to belong somewhere perfectly and to be loved perfectly. God can satisfy that longing.
The reason we don't feel at home here on earth is that we were made for something better, something perfect and full of beauty. We were made for God and a life with him in heaven. Jesus calls to our hearts to come to him and find that life. We have all heard him; we may try to quiet him, but he is there.
"Here I am! I stand at the door and knock. If anyone hears my voice and opens the door, I will come in and eat with that person, and they with me." Revelation 3:20
"This is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent." John 17:3
"No eye has seen, no ear has heard, and no mind has imagined what God has prepared for those who love him." 1 Corinthians 2:9
"Lift up your eyes round about and see; They all gather together, they come to you. Your sons will come from afar, And your daughters will be carried in the arms.
Then you will see and be radiant, And your heart will thrill and rejoice; Because the abundance of the sea will be turned to you, The wealth of the nations will come to you." Isaiah 60:4,5